Background: Calciphylaxis is a rare thrombotic vasculopathy characterized by high morbidity and mortality. There is a paucity of studies examining longitudinal outcomes.

Objective: To assess mortality, days spent in the hospital, and amputations in patients with calciphylaxis.

Methods: A retrospective medical record review was conducted in 145 patients diagnosed with calciphylaxis at an urban tertiary care hospital from January 2006 to December 2018.

Results: Six-month mortality was 37.2%, and 1-year mortality was 44.1%. Patients with nephrogenic calciphylaxis had worse survival than those with nonnephrogenic calciphylaxis (P = .007). This difference in survival disappeared when limiting mortality to deaths due to calciphylaxis. Age (P = .003) and end-stage renal disease (P = .01) were risk factors associated with 1-year mortality. Diabetes mellitus was associated with greater total hospitalization days (coefficient, 1.1; 95% confidence interval, 1.01-1.4); bedside debridement was associated with fewer hospitalization days (coefficient, 0.8; 95% confidence interval, 0.7-0.9). Amputations were not associated with any of the examined risk factors. The use of warfarin followed by a transition to nonwarfarin anticoagulation was associated with decreased hazard of death (P = .01).

Limitations: Retrospective nature.

Conclusions: Calciphylaxis remains a complex, heterogeneous disease. Mortality is lower in patients with nonnephrogenic disease. These findings may be incorporated during discussions regarding the goals of care to facilitate informed shared decision making.